首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   34443篇
  免费   363篇
  国内免费   15篇
教育   25148篇
科学研究   3201篇
各国文化   221篇
体育   2251篇
综合类   13篇
文化理论   559篇
信息传播   3428篇
  2022年   183篇
  2021年   262篇
  2020年   383篇
  2019年   615篇
  2018年   2914篇
  2017年   2809篇
  2016年   2250篇
  2015年   556篇
  2014年   775篇
  2013年   4536篇
  2012年   869篇
  2011年   1371篇
  2010年   1316篇
  2009年   903篇
  2008年   1174篇
  2007年   1626篇
  2006年   491篇
  2005年   791篇
  2004年   822篇
  2003年   721篇
  2002年   482篇
  2001年   479篇
  2000年   415篇
  1999年   361篇
  1998年   204篇
  1997年   224篇
  1996年   244篇
  1995年   238篇
  1994年   183篇
  1993年   201篇
  1992年   323篇
  1991年   308篇
  1990年   299篇
  1989年   300篇
  1988年   259篇
  1987年   304篇
  1986年   266篇
  1985年   305篇
  1984年   249篇
  1983年   211篇
  1982年   193篇
  1981年   166篇
  1980年   155篇
  1979年   260篇
  1978年   182篇
  1977年   168篇
  1976年   154篇
  1975年   141篇
  1974年   147篇
  1971年   140篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Continuous observation of the physical activity of 56 preadolescent children was conducted in four regions of England from October 1988 to July 1989. Observations were undertaken during school break times, lunch times, and physical education lessons, as well as during the children's free time. Of total time observed, the children spent 32.4% of it engaged in moderate to vigorous physical activity (MVPA). Children were shown to be most active during school breaks and least active during free time at home. However, it is thought that cardiorespiratory benefits are best achieved by participation in sustained periods of MVPA. Only 8 (14%) of the 56 children were observed to participate in MVPA for sustained periods of 20 min or longer. A random sample of 55 physical education lessons was observed. Only 6 children engaged in MVPA for sustained periods of 5 min or more, and no children participated in MVPA for 10 min or longer. The implications of these results are that, although the children engaged in a reasonable amount of MVPA, it may not have been sustained for periods of sufficient length to produce a cardiovascular training response. Consideration is given to ways of promoting lifelong involvement in physical activity.  相似文献   
2.
3.
4.
5.
Despite increased enrollment, outcomes such as grade point average (GPA), persistence, and graduation rates for college students with learning disabilities (LD) continue to lag behind those of their nondisabled peers. Reasons for the differences vary but may include academic and social integration, factors identified as important to the success of college students in general. This research investigated the relative influence of background characteristics, precollege achievement, and college integration variables on the academic success and intent to persist of college freshmen and sophomores with LD. While academic and social integration were not unique predictors of college GPA, both integration variables were unique predictors of intent to persist. The findings suggest that beyond high school achievement and background characteristics, college experiences as captured by academic and social integration are promising constructs to help explain the persistence of college students with LD. Implications for future research and practices for high school and college personnel are discussed.  相似文献   
6.
7.
8.
How accurate is the reported percent of students’reaching standards at the school level? How are standard errors for these statistics computed? How do estimates vary with choice of generalizability model?  相似文献   
9.
In recent years university presses have undergone some significant changes, such as expansion of their scope to include materials that may have appeal beyond the scholarly market. This article investigates, through the use of a survey of university libraries, the acquisition of university press products by libraries. In general, recent years have been changes in the relationship between university presses and libraries that have resulted in fewer items being purchased by the libraries.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号